Also set the type when setting the type version

Author: brandtbucher

Lib/test/test_capi/test_opt.py

@@ -2093,6 +2093,25 @@ def testfunc(n):
         self.assertNotIn("_TO_BOOL_BOOL", uops)
         self.assertIn("_GUARD_IS_TRUE_POP", uops)
 
+    def test_set_type_version_sets_type(self):
+        class C:
+            A = 1
+
+        def testfunc(n):
+            x = 0
+            c = C()
+            for _ in range(n):
+                x += c.A  # Guarded.
+                x += type(c).A  # Unguarded!
+            return x
+
+        res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        self.assertEqual(res, 2 * TIER2_THRESHOLD)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertIn("_GUARD_TYPE_VERSION", uops)
+        self.assertNotIn("_CHECK_ATTR_CLASS", uops)
+
 
 def global_identity(x):
     return x

Python/optimizer_bytecodes.c

@@ -118,6 +118,18 @@ dummy_func(void) {
         sym_set_type(left, &PyLong_Type);
     }
 
+    op(_CHECK_ATTR_CLASS, (type_version/2, owner -- owner)) {
+        PyObject *type = (PyObject *)_PyType_LookupByVersion(type_version);
+        if (type) {
+            if (type == sym_get_const(ctx, owner)) {
+                REPLACE_OP(this_instr, _NOP, 0, 0);
+            }
+            else {
+                sym_set_const(owner, type);
+            }
+        }
+    }
+
     op(_GUARD_TYPE_VERSION, (type_version/2, owner -- owner)) {
         assert(type_version);
         if (sym_matches_type_version(owner, type_version)) {

Python/optimizer_cases.c.h

@@ -200,6 +200,10 @@ _Py_uop_sym_set_type(JitOptContext *ctx, JitOptSymbol *sym, PyTypeObject *typ)
 bool
 _Py_uop_sym_set_type_version(JitOptContext *ctx, JitOptSymbol *sym, unsigned int version)
 {
+    PyTypeObject *type = _PyType_LookupByVersion(version);
+    if (type) {
+        _Py_uop_sym_set_type(ctx, sym, type);
+    }
     JitSymType tag = sym->tag;
     switch(tag) {
         case JIT_SYM_NULL_TAG:
@@ -215,18 +219,23 @@ _Py_uop_sym_set_type_version(JitOptContext *ctx, JitOptSymbol *sym, unsigned int
                 return true;
             }
         case JIT_SYM_KNOWN_VALUE_TAG:
-            Py_CLEAR(sym->value.value);
-            sym_set_bottom(ctx, sym);
-            return false;
+            if (Py_TYPE(sym->value.value)->tp_version_tag != version) {
+                sym_set_bottom(ctx, sym);
+                return false;
+            };
+            return true;
         case JIT_SYM_TUPLE_TAG:
-            sym_set_bottom(ctx, sym);
-            return false;
+            if (PyTuple_Type.tp_version_tag != version) {
+                sym_set_bottom(ctx, sym);
+                return false;
+            };
+            return true;
         case JIT_SYM_TYPE_VERSION_TAG:
-            if (sym->version.version == version) {
-                return true;
+            if (sym->version.version != version) {
+                sym_set_bottom(ctx, sym);
+                return false;
             }
-            sym_set_bottom(ctx, sym);
-            return false;
+            return true;
         case JIT_SYM_BOTTOM_TAG:
             return false;
         case JIT_SYM_NON_NULL_TAG:
@@ -266,7 +275,11 @@ _Py_uop_sym_set_const(JitOptContext *ctx, JitOptSymbol *sym, PyObject *const_val
             }
             return;
         case JIT_SYM_TUPLE_TAG:
-            sym_set_bottom(ctx, sym);
+            if (Py_TYPE(const_val) != &PyTuple_Type) {
+                sym_set_bottom(ctx, sym);
+                return;
+            }
+            make_const(sym, const_val);
             return;
         case JIT_SYM_TYPE_VERSION_TAG:
             if (sym->version.version != Py_TYPE(const_val)->tp_version_tag) {